Cigarettes and alcohol in relation to colorectal cancer: the Singapore Chinese Health Study

Abstract

The relations were examined between colorectal cancer and cigarette smoking and alcohol consumption within the Singapore Chinese Health Study, a population-based, prospective cohort of 63 257 middle-aged and older Chinese men and women enrolled between 1993 and 1998, from whom baseline data on cigarette smoking and alcohol consumption were collected through in-person interviews. By 31 December 2004, 845 cohort participants had developed colorectal cancer (516 colon cancer, 329 rectal cancer). Compared with nondrinkers, subjects who drank seven or more alcoholic drinks per week had a statistically significant, 72% increase in risk of colorectal cancer hazard ratio (HR) ¼ 1.72; 95% confidence interval (CI) ¼ 1.33 -2.22). Cigarette smoking was associated with an increased risk of rectal cancer only. Compared with nonsmokers, HRs (95% CIs) for rectal cancer were 1.43 (1.10 -1.87) for light smokers and 2.64 (1.77 -3.96) for heavy smokers. Our data indicate that cigarette smoking and alcohol use interact in the Chinese population in an additive manner in affecting risk of rectal cancer, thus suggesting that these two exposures may share a common etiologic pathway in rectal carcinogenesis.

DNA Repair Single-Nucleotide Polymorphisms in Colorectal Cancer and their Role as Modifiers of the Effect of Cigarette Smoking and Alcohol in the Singapore Chinese Health Study

“…Recent analyses within the Singapore Chinese Health Study have shown that smoking is only a risk factor for rectal cancer (2). We now report that among carriers of the XRCC1 Trp 194 -Arg 399 haplotype, smoking is also a risk factor for colon cancer, in addition to rectal cancer.…”

“…Previously, using the entire cohort database, we reported on the associations between tobacco/alcohol use and colorectal cancer risk (2). Table 1 shows the frequencies of cases and controls by levels of smoking and alcohol consumption within the present nested case-control study set.…”

“…Ever smokers were then asked about age at smoking initiation (four categories: <15, 15-19, 20-29, and 30 years or older), the number of cigarettes smoked per day (six categories: 6 or less, 7-12, 13-22, 23-32, 33-42, and 43 or more), and duration of smoking (four categories: <10, 10-19, 20-39, 40, or more years). As reported previously (2), subjects who began to smoke cigarettes before 15 years of age and smoked 13 or more cigarettes per day were classified as ''heavy'' smokers. The remaining ever smokers were grouped as ''light'' smokers in the present analysis.…”

“…However, rates for this common malignancy in the West have steadily increased in newly affluent Asian Chinese societies, including that in Singapore where rates in both sexes have doubled in the past three decades (1). Recently, we reported that, among Singapore Chinese, cigarette smoking and alcohol drinking were independent risk factors for colorectal cancer (2).…”

“…Singapore Chinese are historically at low risk for colorectal cancer (1,2). However, rates for this common malignancy in the West have steadily increased in newly affluent Asian Chinese societies, including that in Singapore where rates in both sexes have doubled in the past three decades (1).…”